An orally disintegrating tablet that easily disintegrates in the oral cavity is a tablet which can be internally administered without water and is very useful particularly for infants or aged people with a low ability to swallow. Regarding the orally disintegrating tablets, there are available tablets which use hydroxyalkyl cellulose as an additive. For example, PTL 1 suggests an orally disintegrating tablet which contains a hydroxypropyl cellulose having, when prepared into a 20% aqueous solution, a viscosity of 2000 cps or less at 37° C., and having an equilibrium water content of 20% or less at 25° C. and a relative humidity of 75%, and which substantially does not contain any disintegrating agent. Furthermore, PTL 2 suggests an orally disintegrating tablet which contains hydroxyalkyl cellulose microparticles having a volume average particle size of greater than or equal to 0.1 μm and less than 15 μm. PTL 3 suggests a solid preparation which contains a low-substituted hydroxypropyl cellulose having a volume average particle size of 25 μm or less measured according to a dry laser diffraction method, a loose bulk density of 0.35 g/mL or more, and a tight bulk density of 0.60 g/mL or more; and sugars/sugar alcohols.